To lock a folder in windows XP without anysoftware.Follow the steps below.▪▫▫▪▪▫▫▪▪▫▫▪
1.Make a Folder in C drive rename it as"abc" without quotes▪▫▫▪▪▫▫▪▪▫▫▪▪▫▫▪▪▫▫▪
2.Now open Command Prompt from StartMenu▪▫▫▪▪▫▫▪▪▫▫▪▪▫▫▪▪▫▫▪
3.Type "attrib s h C:\abc" without quotes and press enter▪▫▫▪▪▫▫▪▪▫▫▪▪▫▫▪▪▫▫▪
4.This command will Make your folder invisble and it can not be seen even in hidden files and folders▪▫▫▪▪▫▫▪▪▫▫▪▪▫▫▪▪▫▫▪
5.To make it visible again type "attrib -s -h C:\abc
"You can lock any other folder also by changing the location C:\abc to address of your folder.
hope u'll enjoy